EECE 363 Quiz 4B 2008 Solutions

Also find the operating mode of the transistor and

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: m) = 20 μm -3- 3) For the enhancement-type PMOS circuit below, find the values for VD and ID. Also find the operating mode of the transistor and quantitatively justify your answer. Assume ⎛W ⎞ k p ' ⎜ ⎟ = 0.3125 mA/V2, Vt = −1 V, and VA=∞. (Suggested time to spend: 15 min) ⎝L⎠ (6 points) 5V − VSD = 5V + VDS = (1.6 kΩ)⋅ID Assume saturation: ID = (1/2)kp’(W/L)(VGS − Vt)2 = (1/2)(0.3125mA/V2)[−5V − (−1V)]2 = 2.5 mA ⏐VDS⏐=5V − (1.6 kΩ)(2.5 mA) = 1 V ⏐VGS⏐− ⏐Vt⏐= 5V − 1 V = 4 V ⏐VDS⏐< ⏐VGS⏐− ⏐Vt⏐ (Not in saturation) Assume triode: 5V + VDS = (1.6 kΩ){(0.3125mA/V2)[(−5V − (−1V))VDS − (1/2)VDS2]} or 5V + VDS = −2VDS − 0.25VDS2 or (VDS + 2V)(VDS + 10V) = 0 then VDS = −2 V, or −10 V Triode when VDS = −2 V (fulfilling ⏐VDS⏐<...
View Full Document

Ask a homework question - tutors are online